M.P.G. Horse-shoe Case, No. 507. CAKING COAL. The name given to those kinds of bituminous coals which burn readily with a yellow flame and have a tendency to cake, or to run together, in the fire. The Newcastle coals are of this description.

CALAMINE, Dana. See SMITHSONITE. CALAMINE, Jameson, Nicol. Hexagonal. It is found in obtuse rhombohedrons, and in long quadrilateral tables, which are sometimes modified; also compact, mammillated, fibrous, and incrusting other minerals, and occasionally earthy and friable. Colour greyish-white, or yellowish-grey, sometimes inclining to various shades of green and brown. Lustre vitreous, inclining to pearly. Translucent or opaque. Streak white. Yields easily to the knife. Brittle. Fracture uneven. H. 5. S.G. 4 to 4.5.

Fig. 70.

Comp. Zn C-carbonic acid 35·19, oxide of zinc 64.81=100, but frequently containing carbonates of iron, manganese, or lime.

BB flies to pieces and becomes white, but is infusible either alone or with borax. Dissolves with effervescence in nitric acid.

Localities.-English. Huel Mary, Cornwall; botryoidal at Roughten Gill, in Cumberland; mammillated and in crusts at Alston Moor; radiated, of a bluish-green colour, near Matlock, in Derbyshire; the Mendip Hills, in Somersetshire, sometimes in large pseudomorphous crystals after Calcite; crystallized in obtuse rhombohedrons near Holywell, in Flintshire.-Scotch. Lead

Irish. Donegal and Galway. Foreign. A dark brown variety, containing Cadmium, and another of a beautiful bright green, are found at Nertschinsk, in Siberia. Other localities are Dognatzka, in the Bannat of Temeswar, in Hungary; Raibel and Bleiberg, in Carinthia; Tarnowitz, in Si lesia; Altenberg, near Aix-la-Chapelle; near Santander in Spain; &c.

Name. The name is derived from calamus, a reed, because during the process of

ZITE.

CALCAREOUS OPHIOLITE. The name proposed by T. Sterry Hunt for the varieties of Serpentine containing intimate admixtures of Calcite.

CALCAREOUS SPAR. See CALCITE.

CALCAREOUS TUFA. A loose and friable variety of carbonate of lime, deposited in and about waters which are charged with lime. These sometimes form extensive beds, and are well adapted for building purposes, from their softness when first quarried and the hardness they subsequently acquire on exposure to the atmosphere. Some of the beds at the base of the Purbeck formation appear to have been formed after the manner of Tufas, and the tertiary fluvio-marine Limestones of the Isle of Wight also afford other examples of Calcareous Tufas, having evidently been deposited at the bottom of lakes impregnated with lime, or, in some cases, subaerially. Calcareous Tufa is frequently formed on the leaves and stems of plants, which are then said to be petrified or converted into stone, and the waters which possess this property are called petrifying springs. At Matlock there are springs of this description, where objects speedily become incrusted with carbonate of lime; but in Italy there are very extensive deposits of Calcareous Tufa, as at Terni, and on the banks of the river Anio, near Tivoli. (See TRAVERTINE.) The temples of Pæstum are built of Tufa, which has become hardened by time and exposure; to which circum

CALDERITE.

Comp. Ca C-carbonic acid 44, and lime 56 = 100; often with some carbonate of magnesia or iron.

BB infusible; alone on charcoal it shines with intense brightness when all the carbonic acid is expelled, and becomes converted into pure lime or quicklime. With fluxes behaves like Aragonite. Some varieties, as that accompanying Garnet in Wermeland, Laumonite in Brittany, shine with a yellow phosphorescent light when laid on a hot coal, or struck in the dark.

Effervesces violently with acids.

The purest form of Calcite is Iceland Spar, which in common with other transparent varieties is doubly refractive in a high degree. The different species will be described under their proper names.

Localities. This mineral is so universally distributed, that it is only possible to give a list of its most remarkable localities. Sixsided prisms of great beauty have been found at Andreasberg in the Harz. In England fine specimens are chiefly found in Cornwall, Devonshire and Derbyshire; in Wales, in Flintshire; in Scotland, at Strontian, Argyleshire; and in Ireland, at Kingston Cave, near Cahir, co. Clare. In Cornwall low hexagonal prisms and tabular forms prevail, like figs. 74 and 76. Fig. 82, represents the crystals from the Breakwater quarries at Plymouth. This fig. and figs. 79, 80, and 83, are the forms most common in Derbyshire, and at Alston Moor; fig. 79, being that called by the Derbyshire miner "Dog's-tooth Spar." In the neighbourhood of Alston, and at Garrigill in Cumberland, the crystals have commonly a hexagonal character, as represented in figs. 71, 73, 74, 77, 78, and 81. Fig. 77 represents a form met with at Dufton and Patterdale in Westmoreland.

Name. From the Latin calx, lime.
Brit. Mus., Cases 42 to 47.

M. P. G. Principal Floor, Wall-cases 27, 28, and 30: Horse-shoe Case, Nos. 367 to 391.

CALDERITE. A massive variety of Garnet from Nepal.

CALEDONITE, Beudant, Greg & Lettsom.

BB on charcoal, easily reduced. Partially soluble, with slight effervescence, in nitric acid.

Localities. Found in flattish crystals accompanied by other ores of lead, at Leadhills in Lanarkshire, and with Cerussite and Leadhillite at Roughten Gill in Cumberland: also said to occur at Tanné in the Harz, and at Mine la Motte in Missouri. The crystals are generally very minute, and appear sometimes in small bunches radiating from their common point of attachment to the matrix.

Brit Mus., Case 55. CALLAIS. See TURQUOIS. CALLAITE, Allan, Fischer, Phillips, Nicol. See TURQUOIS.

The name

CALLIMUS, J. Woodward. given to the stony matter contained in the cavities of Etites, when it is loose and moveable.

CALOMEL, Beudant. Pyramidal. Sometimes occurs crystallized in distinct quadrangular prisms terminated by pyramids: also in tubercular crusts; sometimes fibrous, rarely compact. Colour greyish-white grey, yellowish, greenish-grey, brown : occasionally translucent, with an adamantine lustre. Sectile. Fracture conchoidal. H. 1 to 2. S.G. 6.48.

62

CALSTRON BARYTE.

CANTALITE.

CANCRINITE. Hexagonal. Occurs in six and twelve-sided prisms, sometimes with the basal edges replaced: also thin columnar and massive. Colour white, yellow, green, blue, grey, reddish. Lustre vitreous at the fractured surfaces, greasy in other parts. Transparent or translucent. H. 5.5 to 6. S.G. 2.42 to 2.62.

Comp. According to Breithaupt, this mineral is identical with Davyne. 2 [Na2 Si+2 Al Si + (Na Ċa) Ċ] +3H. P. v. Pusirewsky. Analysis, by Whitney, from Litchfield, U.S.:

but not before.

Localities. Of a light rose-red colour in the Ilmen mountains (S.G. 2·489); of a citron-yellow colour at Marünskaja, in the Tunkinsk mountains, 400 wersts from Irkutsk, in coarse granite (S.G. 2.454); and crystallized and massive in the United States at Litchfield, in the State of Maine.

Name. After Cancrin, a Russian minister of finance.

CANDITE, Bournon. Pleonaste found associated with Tourmaline, &c., loose in the rivers and alluvial district around Kandy, (whence the name Candite,) in Ceylon.

CANEHLSTEIN, from Cannel (Dutch). See CINNAMON STONE

CANNEL COAL. Cannel is a corruption of the word Candle, which has been applied to a particular description of Coal, either because in burning it gives out a bright flame like that of a candle, or because, in some places, poor people use it instead of lights.

It is a bituminous substance, and is supposed to have been formed from decomposed vegetable matter in water, in the finest state of division. It differs from the purer kinds of ordinary Coal and Jet, in containing extraneous earthy matters, which render it specifically heavier than water; Jet, on the contrary, being lighter. It is hard enough to take a fine polish, and is made into inkstands, snuff-boxes, beads, and other ornamental articles. (See also PARROT COAL.) S G. 1.23. Cannel Coal has a resinous glistening lustre, and a dark greyish-black colour. It is very compact, breaking with a conchoidal fracture, into irregular or cubical fragments. The Cannel Coal of Lesmahagow on distillation yields 40 gallons of crude oil, and 30 gallons of rectified oil per ton.

It is found in England near Whitehaven, at Wigan in Lancashire, Brosely in Shropshire, and Athercliff, near Sheffield; and in Scotland at Lesmahagow in Lanarkshire, Boghead in Linlithgowshire, Gilmerton near Edinburgh, West Wemyss in Fife, and Muirkirk in Clydesdale.

M.P.G. Horse-shoe Case, Nos. 70 and 78. Upper Gallery, Wall-cases 41, No. 161, and 43, Nos 149, 150.

CANOXINITE, Bischof. A mineral consisting of the silicates of soda and alumina, and carbonate of lime, from the Miasget in the Ural. There are three varieties found in the granite of Litchfield (Maine, U.S.), consisting of the silicates of soda and alumina, with carbonates of lime and soda.

CANTALITE. A variety of Pitchstone containing crystals of Glassy Felspar. Colour